Although the advent in the pleasure boat field of personal ski boats and the like brought a plethora of streamlined and stylish ski boats to satisfy those of all persuasions as to boat styles and sizes, the trailers for supporting and transporting this new personal phenomenon of the boating industry remained of the work horse type. Thus the contemporary trailers comprised a generally box-type frame with cross members supported by conventional brackets, either bunk or roller units, and with one or more vertically upright posts on the tongue or interior frame members for supporting winches. Although these ski boat trailers were functional, they were certainly susceptible to structural and design improvements to bring them at least even with the innovations of that which they carried, the personal watercraft. Improvements of such contemporary trailers have been made as to two-place personal watercraft trailers as shown in my copending application Ser. No. 08/164,349, and it is seen herein that certain other improvements are incorporated in a single place personal watercraft trailer.